Electrical heating unit.



A1 N. MACNICOL.

ELECTRICAL HEATING UNIT.

APPLlcAloN immune-16.1914.

Znvenorf M h.' ww

Mzorney.

UNITED STATES PATENT oFErcE.

ARNOLD NESBITT MACNICOL, OF MELBOURNE, VICTORIA, AUSTRALIA.

ELECTRICAL HEATING UNIT.

To all 'whom t may concern: v

Beit known that ARNOLD Nnsnrr'r MAC- MCoL, a citizen of the Commonwealth of Australia, residing at 31 Queen street, Melbourne, in the State ol Victoria and said Commonwealth, has invented an Electrical Heating Unit, of which the following is a specification, reference being had therein to the accompanying dran-'ings This invention relates to electrical heating units and has for its object to provide an improved constructionI of heating unit which is cheap, eiiicient ,in use, and the parts of which are readily detachable and renewable, the unit' being applicable to cooking stoves, hot plates, domestic and soldering irons, kettles and other utensils and for' electrical heating purposes generally.

According to this invention the unit consists of a cylindrical support or bar, of magnesiumL silicate formed in sections, each section being provided with axially or diagonally arranged holes, grooves or slots, adapted to carry a high resistance Wire or Wires therein, means. being provided for connecting the said wire or Wires to the main leads. If'desired means may be provided for locking the Wire or wires at the` segment joints and the Wire or Wires may, after having been placed in position in the grooves, be embedded therein by a filling material consisting of magnesium silicate and a carbo-hydrate with or Without the addition of plaster of Paris.l

I will describe, with reference to the accompanying drawings, a construction in accordance with this invention but Il do not limit myself to the precise details of construction described and illustrated'.

Figures l and 2 are respectively an elevation andend view of a construction in accordance with my invention.

Figs. 3 and i are respectively a longitudinal section and a cross section of the construction sho-vn in Fig. 1, Fig. t being taken on the line -b, Fig. 1.

Figs. 5 and 6, 7 andI 8, are respectively end views and cross sections of n1odica--` tions of the construction shown in Fig. 1.

Referring to Figs. 1 to 4 inclusive, the

heating unit consistsyof a cylindrical suport 1 or bar of magnesium silicate, formed y m sections 13, thereby facilitating the bor- VVing of the axial holes 2 immediately inside the external surface of the bar or rod forming the support. Each unit 1s made up of Specification of Letters Iatent.

Patented Feb. 5, iiS.

Application tiled .T une 16, 1914. Serial No. 845,487.

a pluralityof sections arranged in line with each other, and for Wiring the holes in each sect1on are arranged in vline as shown. These sections may be connected by a lap joint 13a or socket 13b, or they may rest iiush against each other as illustrated. The ends are fitted with caps 14. Vthe whole being se cured together as a compact support by the bolt 15 passing through a central hole 18 and provided with a nut or nuts 16. Means are provided for connecting the resistance wire Ior Wires to the main leads, the said means consisting of terminals 17, 17. One or both end sections of the support is provided With a projecting flange 4.- to facilitate Winding and to prevent short circuiting.

By these means the sections 13 are held.

lfirmly together and after the coil, or coils of Wire, or the Winding have been arranged in the holes 2, each section may be given a partial turn, so that the Wire, or Wires at each joint may be held or locked by the edges of the corresponding lholes in the adjacent sections, in which position the holes would not be in alinelnent, so that anumber of small coils, each containin a lshort length of coil, of high resistance Wire is thus formed. This arrangement eii'ectually prevents short-circuiting and allows the turns of Wire t0 be arranged closely together.

ln the construction shown in Fig. 5 the holes may be arranged concentrically Within the outer surface of the cylindrical support or bar 1, the resistance coil or coils being Wound or threaded therein as will be readily understood.

In the construction shown in Figs. 6 and 7 the cylindrical support 1 or bar of basic material is formed with a number of axially arranged holes, slots or grooves adapted to carry the Wire, or Wires. When it is desired. to heat quickly, the unit may be provided with drilled ducts 15b communicating with `the external surface by means of saw cuts,

at' thebottom or top of the grooves 17b and formed in either side thereof. Fig. 7 shows a. construction in which th grooves 17" are arranged parallel and around `the periphery and longitudinally of the support 1. Each groove 17 b projects toward the center of the cylindrical support which is formed as before in sections, the said grooves penetrating the support to a suitable depth along the length thereof. The high resistance Wire, or coil is arranged in the grooves 17a and is connected in circuit, the return wire being passed through a central hole 13a or in any other convenient-manner. The support so constructed may be inserted in a suitable glass, metal, or other'casing 19 and the lead Wires be connected to suitable switch devices and to the source of electrical supply. The grooves may be arranged at an angle to the center so that when the Wire 3 is in position eachsection 13 may be given a partial turn, the grooves 17 b of the next section taking the opposite position or direction, illustrated by dotted lines in F ig. 8, thus giving the Wire 3 an eXtra lock at the joints of the sections, and thereby obviating the risks of short circuits and allowing the coils of the Wire 3 to be Wound close together so as to give greater efficiency While at the same time a number of single cells are formed each containing a short length or coil of resistance Wire.

The angle of the grooves or slots in Figs. 7 and 8 is preferably reversed in each section so that the grooves or slots in adjacent sections are arranged at opposite angles whereby, b y slightly turning the said adja cent sections, the Wire is securely locked in the bottom of the grooves.

When `Wire or Wires are arranged in grooves, or slots in the exterior surface of the support the said Wire or Wires may be Lamaze embedded in or covered With a filling material b (Fig. 7 consisting of basic material (magnesium silicate) in powder form and a carbohydrate with or Without the addition of calcium sulfate, so as to impart a slight conductivity thereto.

In a heating unit formed with an equal number of slots, the return Wire would lead from the same end, but should an unequal number of slots be employed and if it be desired that the terminals be positioned at one end, the Wire would return through the center.

What claim as my invention and desire to secure by Letters Patent, is-

1. An electrical heating unit consisting of a cylindrical support formed in sections, said sections having longitudinally arranged holes therein; a high resistance Wire therein, the arrangement being such that by partial rotation of a section or sections the Wire or Wires may be locked at the joints of the said sections, substantially as described.

2. An electrical heating unit consisting of a support formed of a plurality of sections adapted to be moved into engagement one With the other, said sections having holes formed therein, a resistance Wire 1n said holes, the arrangement being such that by the movement of the sections the Wire may be locked at the joints of said sections, substantially as described.

In testimon, whereojl I affix my signature in presence o two Witnesses.

ARNULD NESBETT MACNCOL Viitnesses:

DOROTHY A. Caow'rnnn, ANNE E. Eowenns..

Gayle: o! this patent may be obtained :for five sente each, by netmeeting the Qeinmssener of Paten-tl,

Washington, B. G." 

